Conventional blister packs are commonly used in the packaging of various products. Such packages are desirable in that the product or item is visible to the consumer and are substantially air- and moisture-tight due to the sealing of the plastic film which is used to form the blister to the package base or backing. The problem with this type of packaging is that the blister pack is difficult to open when it is desired to remove the product or item from the package.
U.S. Pat. No. 2,105,367 discloses a flexible wrapper including preformed weakened zones to facilitate opening the package. The weakened zones comprise notches and a tab to pull a portion of the wrapper in a fixed direction to tear open the package.
U.S. Pat. No. 3,078,986 describes a blister having a polyethylene cover sheet secured to the blister with a corner cut away to facilitate grasping and removal of the lid.
U.S. Pat. No. 4,398,634 employs slits or cuts as indicia to direct the user to the proper position for opening of the package for removal of individual units.
U. S Pat. No. 4,781,294 describes a tear-oriented package formed of a pair of wall members sealed together, at least one of the wall members being formed of foamed polypropylene material to facilitate the tearing of the one wall member to open the package in a pre-determined direction while resisting the opening of the package in other directions. An H-shaped die cut is formed in the foamed polypropylene member over which a tab is placed to facilitate opening of the package.
While these designs facilitate opening of blister-type packages, there is a need for an improved opening feature which is a simple to use and economical to manufacture.